Process for the production of azo-dyestuffs on acidyl cellulose



Patented Feb. 11 1931 UNITED STATES PATENT OFFICE FRIEDRICH AND WOLFGANG J'AECK, F BASEL, SWITZERLAND, ASSIGNORS T0 SOCIETY OF CHEMICAL DSI'DUSTRY m BASLE; 0F BASEL, SWITZEBLAIID v PROCESS FOR TEE -PROIlJUC'1 IQN OF AZO-DYESTUFFS ON ACIDYL CEI-LULOSE m Drawing. Application filed November 28,

1927, Serial). 236,360, and in Switzerland December 4; 1926.

, The present inventionrelates to a process for the production of dyestuifs valuable for the production of fast tints on acidyl cellulose: It comprises the process of producing 5 these dyestuffs, and the material dyed according to the new process.

' It has been found that new dyestuffs are obtained which are valuable as pigments by treating the diamino-azo-dyestutfs of the general formula:

NH R N=NR NH V wherein R and R signify two aryl residues which may be different from each other, with nitrous acid, and coupling the compound thus obtained in a medium in which pH is smaller than 7.1 with a compound of the general formula:

in which a; means H- or COOH. The products thus obtained the, general formula:

correspond to OH H0 The following example illustrates the invention, the parts being by weight Example 12 parts of a paste made by stirring with 200 parts of a suitable distributing agent, 50 parts of the diamino azo-dyestulf obtained by saponifying the coupling product from-diazotized paraaminoacetanilide and cresidine, are emulsified at 60 C with 80 parts of soap solution of 10 per cent. strength and the suspension is diluted with lukewarm water to about 4000 parts:

Into the dye-bath thus prepared the thoroughl'y wetted acetate silk (100 parts) 'is entered and dyeing is continued for about an hour, the temperature being gradually raised to 75 C. The yellow dyed acetate silk n isthen washed, in the course of 30 minutes treated with 3-4 parts of sodium nitrite and 9-12 parts of hydrochloric acid, amounting f to 1/20th of the liquor, and the dyeing is then developed in a bath at 60 C. of B-hydroxynaphthoic acid acidified with an acid the pH of which in a. 1/10. normal solution in water lies in the neighbourhood of 3 and contain ing 3-4 parts of B-hydroxynaphthoic acid.

Thesilk is then washed, if necessary soaped, and brightened as usual. Deep black shades are obtained of excellent fastness. .The formula of'the new dyestufi is very probably the following:

J 0H. on no oon- Hoo Y With ,B-naphthol in a feebly acid coupling 4 bath there are also obtained deep black shades which, however, have not the outstanding fastness to light of the dyeing de-. veloped with ,B-hydroxynaphthoic acid. The

probable formula of the ,B-naphthol dyestuff is: a

' in the first paragraph of this example may be named aqueous solutionsof sulphonic acid salts, such as delimed'sulphite cellulose lye, condensation products of formaldehyde and naphthalene sulphonic acids, sulphonation products of the residues from the manufacture of organic compounds such as benzaldehyde, humin substances and soap solutions.

What weclaim is 1. A process for the production of azo-dyestuffs of the probable general formula:

OH HO wherein R and R signify aryl residues which may be 'difierent from each other, and a: means H or COOH, on acidyl cellulose, consisting in firstly dyeing acidyl cellulose with diamino-azo-dyestufis of the general formula NH R "N=NR NH wherein R and R have the above identified signification, then treating the dyed material with nitrous acid, and finally coupling it in a medium in which pH is smaller than 7.1, with compounds of the general formula:

' wherein a: has the above identified signfication.

2. A process for the production of azodyestuffs of the probable general formula: N=N R1N=NB2-N=N wherein R and R signify aryl residues which may be different from each other, and as means H or COOH, on acetyl cellulose, consisting in firstly dyeing acetyl cellulose with diamino-azo-dyestufis of the general formula:

wherein R and R have the above identified signification, then treating the dyed material with nitrous acid', and finally coupling it in a medium in which pH is smaller than 7.1, with compounds of the general formula:

wherein as has the above identified signification.- l 3. A process for the production of azodyestufis ofthe probable general formula:

COOH HOOC wherein R and R signify aryl residues which may be different from each other, on acidyl cellulose, consisting in firstly dyelng acidyl cellulose with diamino-azo-dyestufi's 9 of the general formula:

NH2R1N=NR2NHI, wherein R and R have the above identified signification, then treating the dyed material with nitrous acid, and finally coupling it in a medium in which pH is smaller than 7.1, with ,B-hydroxynaphthoic acid.

4. A process for the production of amdyestuffs of theprobable general formula:

COOH HOOC wherein R and R signify aryl residues which may be different from each other, on acetyl cellulose, consisting in firstly dyeing acetyl cellulose With diamino-azo-dyestulfs of the general formula:

wherein R and R have the above identified signification, then treating the dyed material with nitrous acid, and finally coupling it in a medium in which pH is smaller than 7.1, with B-hydroxynaphthoic acid.

5. A process for the production of amdyestufis of the probable general formula:

coon H00 wherein R and R signify aryl residuesof the benzene series which may be different from each other, on acidyl cellulose, consisting in firstly dyeing acidyl cellulose with diamino-azo-dyestuifs ofthe general formula:

wherein R and R have the above identified signification, then treating the dyed material with nitrous acid, and finally coupling it in a medium in which pH is smaller than 7.1, with ,B-hydroxynaphthoic acid.

6. A process for the production of azodyestufis of the probable general formula:

on acetyl cellulose, consisting in 'firstly dyeing acetyl cellulose with the diamino-azodyestuff of the formula:

C H; NHQN=NONH2 then treating the dyed material with nitrous acid, and finally coupling it in a medium in which pH is smaller than 7.1, with ,B-hydroxynaphthoic acid.

In witness whereof we have hereunto signed our names this 17th day of November, 1927.

FRIEDRICH FELIX. WOLFGANG JAECK.

it in a medium in which pH is smaller than 7 .1, with B-hydroxynaphthoic acid.

7. A process for the production of amdyestufis of the probable formula:

H HO

coon H000 on acidyl cellulose, consisting in firstly dyeing acidyl cellulose with the diamino-azo-dyestufi' of the formula:

0H; HQ =N NH.

then treating the dyed material with nitrous acid, and finally coupling it in a medium in which pH is smaller than 7.1, with ,B-hydroxynaphthoic acid.

8. A process for the production of azo-dyestuffs of the probable formula:

H HO

COOH H00 

